A large variety of systems, both natural and artificial, are composed by interconnected units embedded in space. All these systems can be mapped onto spatial networks [1]}, [2]}, a powerful framework which provides the mathematical and conceptual tools to study them formally. Such a framework, built on basic common features, applies to a broad diversity of contexts: from transportation [3]}, [4]}, [5]}, [6]}, [7]} to biology [8]}, [9]}, from neuroscience [10]} to animal behavior [11]}, [12]}, [13]}, from epidemiology [14]}, [15]}, [16]} to communications [17]} and migrations [18]}, to cite a few.
